*One in series of post to documents our experiences with a variety of health problems and how we, with our vet's guidance, treated them. This is in no way an attempt to create a comprehensive health care guide. We aren't vets, we just spend a lot of time (and money) at our vet's office...and unfortunately that is because there are a lot of health problems possible with rats. If I can give only one piece of advice to a new rat owner, it is get a good vet. Experience treating rats is good (I was quite pleased when our vet picked up Rizzo for the first time and said "These are my favorite of the pocket pets"), but so is a willingness to research and listen to what you've learned on your own.
Almost immediately upon bring Rizzo and Krycek home I started seeing red stains in their bedding. My first assumption was, of course, blood, although I didn't see any wounds on either of them. I hit the search engines and found that rats produce porphyrin, a red discharge, around their eyes and nose, particularly when they are ill or stressed. The question of what caused the red stains was quickly answered: I woke up one day to such quantities of red, not just on the bedding but on the walls behind the cage, that it was clearly blood. The rats, cage and all, went directly to the vet for our first panicked emergency visit. He found very small nicks on both rats, either scratches or bites, and that began the days of separate cages for the girls.
I am still not completely sure how to tell the difference between blood stains and porphyrin stains. I think that the porphyrin is lighter (looks maybe like watered-down blood) and when we've seen porphyrin staining, it's usually a fine mist pattern from a rat's sneeze.